共查询到20条相似文献,搜索用时 46 毫秒
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随着厚膜微电子技术的快速发展,在其生产过程中,丝网印刷对于整个生产的影响和作用越来越受到生产设计师和工艺师的重视。掌握和运用好丝网印刷技术,分析其中产生问题的原因,并将改进措施应用在生产实践中,不断获得更好的丝网印刷质量,是大家所期望的,本文就丝网印刷中影响质量的因素做一些探讨。 相似文献
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丝网印刷在印制电路板(PCB)上具有得天独厚的优势,文中通过分析丝网印刷和电路板印制的特点,介绍电路板丝网印刷各工序的技术要点,以及电路板丝网印刷常用的几种油墨的应用方法。 相似文献
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由于印刷线路板的线宽和线间间隔的细微化,以往不引人注意的离子迁移现象已经对线路板的绝缘性能造成影响.本文介绍了这种现象发生的原因和研究动向.使离子迁移并成为影响绝缘性能的因素有印刷线路板的材质及加工工艺,也和结构设计和使用环境有关. 相似文献
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设计了一种用于丝网印刷机的印刷间距调整系统,能够对丝网印刷间距进行实时精确调整,并在丝网印刷机中验证了该系统能够提高印刷品质,稳定工作。 相似文献
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一 碱性蚀刻:
碱性蚀刻的基本机理就是碱性氯化铜化学反应。是二价铜离子氧化金属铜生成亚铜离子。这种平衡同样在酸性氯化铜中的二价铜氧化浸蚀铜金属。所以在碱性环境条件下。发生亚铜离子和二价铜离子的氨的络合物。更进一步利用通人空气使酸性氧化铜蚀刻液中亚铜离子氧化成二价铜离子。 相似文献
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在印制电路板过程中,焊膏印刷的效果对产品质量关系很大。文章主要探讨焊膏丝网印刷过程中操作技术要点和应注意的问题,以及一些常见故障的处理方法。 相似文献
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采用丝网和钢网印刷工艺可以在晶圆背面大区域内进行快速而均匀的覆膜.丝网印刷工艺有较好的工艺能力,钢网印刷覆膜厚度均匀性受制于机器的平面度. 相似文献
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文章阐述了电化学迁移对印制电路板绝缘性的破坏,并分析了CAF现象的成因和影响因素,介绍了改善基材耐CAF性能的方法。 相似文献
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Bo-In Noh Jeong-Won Yoon Won-Sik Hong Seung-Boo Jung 《Journal of Electronic Materials》2009,38(6):902-907
This study investigated the influence of three parameters, the distance between electrodes, bias voltage, and surface finish
material, on the electrochemical migration (ECM) in flexible printed circuit boards (FPCBs) during water drop testing. The
ECM rate increased when the distance between electrodes of opposite polarity was decreased and the bias voltage was increased.
Irrespective of the distance between the electrodes and the bias voltage, the growth rate of dendrites from the cathode to
the anode decreased with the following order of surface finish material: Cu, electroless Ni, and electroless nickel-immersion
gold. The order of the corrosion rate in distilled water with pH 6.5 was the same. Therefore, the ECM rate on the FPCB increased
with increasing corrosion rate of the FPCB surface finish material. 相似文献
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研究了不同钯(Pd)含量银合金线的电阻率、铝挤出、可靠性及横截面的情况,并分析了Pd抑制银离子迁移的原理。结果表明,银合金线中加入Pd后,Pd的含量越高,线材的FAB硬度越大,铝挤出越多,Pd有助于提高合金线的可靠性,同时Pd的质量分数到3%以上时其可靠性更好。Pd能够抑制银离子迁移的原因是表面形成了一个PdO层,PdO富集在表面阻碍银离子扩散及迁移。银合金线的Ag-Al焊球界面主要形成Ag2Al及Ag3Al,Ag2Al比Ag3Al具有更高的抗腐蚀能力。 相似文献
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在制造薄膜开关电路层或RFID标签天线层时,银层(导线)的银(碳)浆通常是用丝网印刷来完成的。在丝网印刷银浆中,银层产生断裂(裂缝)是常见的故障之一,它严重影响产品的质量,甚至成为废品。因此,在电路导线的银浆丝网印刷中要引起重视。文章主要分析探讨银浆丝网印刷中产生导线断裂(裂缝)的原因和防治对策。 相似文献
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Weiqiang Wang Anupam Choubey Michael H. Azarian Michael Pecht 《Journal of Electronic Materials》2009,38(6):815-827
The worldwide transition to lead-free electronics has increased the usage of several lead-free pad finishes for electronic
assembly manufacturers, including immersion silver, immersion tin, electroless nickel-immersion gold, and organic solderability
preservatives. This study assesses and compares immersion silver as a circuit board finish in terms of its ease of use, wettability,
solderability, shelf life, appearance, solder joint strength, intermetallic and void formation, reliability, and costs. 相似文献
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Sebastian B. Meier Stephan van Reenen Bastien Lefevre David Hartmann Henk J. Bolink Albrecht Winnacker Wiebke Sarfert Martijn Kemerink 《Advanced functional materials》2013,23(28):3531-3538
Using a planar electrode geometry, the operational mechanism of iridium(III) ionic transition metal complex (iTMC)‐based light‐emitting electrochemical cells (LECs) is studied by a combination of fluorescence microscopy and scanning Kelvin probe microscopy (SKPM). Applying a bias to the LECs leads to the quenching of the photoluminescence (PL) in between the electrodes and to a sharp drop of the electrostatic potential in the middle of the device, far away from the contacts. The results shed light on the operational mechanism of iTMC‐LECs and demonstrate that these devices work essentially the same as LECs based on conjugated polymers do, i.e., according to an electrochemical doping mechanism. Moreover, with proceeding operation time the potential drop shifts towards the cathode coincident with the onset of light emission. During prolonged operation the emission zone and the potential drop both migrate towards the anode. This event is accompanied by a continuous quenching of the PL in two distinct regions separated by the emission line. 相似文献